Butter warmer



FIG. 1 is a front view of a butter warmer, showing my new design;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a back elevational view thereof; and,

FIG. 7 is a top perspective view.

The dotted lines showing a candle in FIG. 7 are environmental only and form no part of the claimed design. 

The ornamental design for a butter warmer, as shown and described. 